Asia is now the top contributor of spam among all continents, accounting for over half of all spam messages relayed globally, reveals a new report released Wednesday.
In its report for the third quarter of 2011, Sophos said the percentage of spam originating from Asia increased to 50.1 percent, marking a sharp increase from the same quarter last year when Asia was responsible for only 35.1 percent of all spam.
Although the United States remained the "single worst offender", topping the list of countries from the spam originated, Asian nations contributed a significantly higher proportion of spam. South Korea jumped up five spots in the "Dirty Dozen" list to come in second after the U.S., contributing to 9.6 percent of total spam e-mail.
Several Asian nations--Indonesia, Pakistan, Taiwan and Vietnam--also joined the Dirty Dozen list since the third quarter of 2010. India dropped to third place behind South Korea, responsible for relaying 8.8 percent of the world's spam.
"These latest statistics suggest that as more people get online in Asia, they are not taking the right steps to protect their computers from infection which results in the growth of botnets," Graham Cluley, senior technology consultant at Sophos, said in the report.
He added that spam which attempts to smash its way into users' e-mail accounts can vary from being "annoying adverts" to "downright malicious attacks". In the worst cases, a spam message might be designed to infect the victim's computer with a Trojan horse or phish his banking credentials, Cluley said.
The majority of spam e-mail messages were distributed by botnets, which are networks of infected machines or zombies operated by the spammers.
Computer users risk becoming botnets when they do not run updated antivirus software and the latest security patches. This issue is not limited to traditional e-mail and include social networking services which can be exploited by fraudsters to spread money-making surveys via spammed out messages, Sophos warned.
"If you receive spam messages, check any filter settings you may have and make sure your security software is running and has the latest patches installed," Cluley advised. "Don't ever be tempted to buy anything via spam as that's what makes it worthwhile for the spammers."
He also warned that botnets can be used by cybercriminals to launch Distributed Denial of Service attacks (DDoS), where thousands of zombie computers are used to connect to a specific Web site, forcing it to go offline as it struggles to cope with the increase in traffic.